onsemi KSC5019NTA

Overview

KSC5019NTA from ON Semiconductor is an NPN epitaxial silicon transistor designed for medium-power switching and linear amplification in consumer and industrial electronics. It delivers V_CE(sat) = 0.5 V at I_C = 2 A / I_B = 50 mA, supports V_CEO = 10 V, I_C = 2 A DC, and operates up to T_J = 150°C - commonly used in relay drivers, power supply control stages, and LED load switches.

For engineers reviewing the KSC5019NTA datasheet, pinout, applications, or equivalent options, key selection criteria include saturation voltage under high-current drive, DC current gain (h_FE = 70–200 at I_C = 2 A), thermal resistance (R_θJA = 160°C/W), TO-92 package compatibility, and safe operating area limits for pulsed loads.

Technical Context

The KSC5019NTA is a general-purpose bipolar junction transistor with emitter-common configuration, optimized for low-saturation switching in DC-coupled circuits. Its h_FE classification (N-grade: h_FE1 = 300–450 at I_C = 0.5 A) and f_T = 150 MHz support stable gain in audio-frequency amplifiers and fast turn-on in pulse-width modulated loads.

It features V_CEO = 10 V and V_CBO = 30 V, indicating suitability for low-voltage collector circuits with moderate base-collector reverse bias tolerance. The device's Cob = 27 pF at V_CB = 10 V and R_θJA = 160°C/W define its high-frequency response ceiling and thermal derating behavior on standard FR-4 PCBs.

Key Specifications

Pinout & Package

Package: TO-92, 3-lead molded plastic case with straight or bent leads (standard ammo packing). Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base - verified per Fairchild KSC5019 Rev. 1.4 mechanical drawing and pin assignment diagram.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN switching transistor applications.

Compared with MJD127G and BC547C, the KSC5019NTA uniquely balances TO-92 form factor, 2 A DC current handling, and 10 V V_CEO - making it optimal for cost-sensitive, medium-power switching where thermal budget and board space are constrained.

Availability

KSC5019NTA is available at Aetrix Electronics and suitable for relay drivers, LED load switches, and DC-DC converter control stages requiring stable component supply, long-term manufacturability, and consistent parametric performance across production batches.

Supply support for KSC5019NTA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and consumer markets.

The KSC5019NTA belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild Semiconductor for cost-effective, robust switching and amplification in high-volume commercial electronics.

FAQ

What is the maximum continuous collector current rating for the KSC5019NTA?

The KSC5019NTA has a maximum continuous collector current (I_C) rating of 2 A at T_A = 25°C. This value is validated per Absolute Maximum Ratings in the official datasheet and assumes proper PCB thermal management. Exceeding 2 A DC requires derating based on ambient temperature and board layout - the KSC5019NTA must not be operated above its 750 mW power dissipation limit without thermal consideration.

Does the KSC5019NTA have a specified h_FE range at high collector current?

Yes - the KSC5019NTA specifies h_FE2 = 70 to 200 at V_CE = 1 V and I_C = 2 A, confirming usable DC current gain under full-load switching conditions. This range is measured and binned per the N-grade classification (h_FE1 = 300–450 at I_C = 0.5 A), enabling reliable base drive calculation for the KSC5019NTA in production designs.

What is the pin configuration of the KSC5019NTA in TO-92 package?

The KSC5019NTA uses standard TO-92 pinout: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base - confirmed in the mechanical drawing (Figure 7) and schematic symbol of the KSC5019 Rev. 1.4 datasheet. This configuration is consistent across all KSC5019 variants and aligns with JEDEC TO-92 orientation conventions for NPN transistors.

Can the KSC5019NTA be used in linear amplifier applications?

Yes - the KSC5019NTA supports linear operation with f_T = 150 MHz, Cob = 27 pF, and h_FE stability across I_C = 0.01–2 A. Its V_CEO = 10 V and low noise characteristics make it suitable for audio preamplifier stages and sensor signal conditioning, provided biasing remains within SOA limits and thermal design accounts for dissipation at quiescent current.

What is the thermal resistance (R_θJA) of the KSC5019NTA on a standard PCB?

The KSC5019NTA has a junction-to-ambient thermal resistance (R_θJA) of 160°C/W when mounted on a standard FR-4 PCB measuring 76 mm × 114 mm × 1.57 mm with minimum land pattern. This value directly determines allowable power dissipation - for example, at 50°C ambient, max safe P_D ≈ 470 mW before reaching T_J = 150°C - a critical constraint for sustained operation of the KSC5019NTA.